Technical Field
[0001] This invention relates generally to electrical connectors and more particularly to
push-in electrical connectors.
Background Art
[0002] In branch wiring of electrical circuits, it is common to electrically interconnect
two or more wires. Individual wires may be bent about a screw type conductive stud,
with the stud tightened about the wires. Other electrical connectors employed in the
past have included "spring" type connectors in which the exposed ends of the wires
are twisted together and inserted into a common cavity within an insulating body.
A spring or coil is mounted within the common cavity and secures the twisted ends
of the wires within the connector and ensures common electrical interconnection between
the wires.
[0003] U.S. Patent No. 3,638,171, issued to Hulbrechtse, is an example of a "push-in" type
connector incorporated into an electrical outlet. The push-in connector includes individual
passageways for insertion of the exposed end of a wire. An electrically conductive
beam member is mounted within the passageway for sliding contact with the wire within
the passageway. As the wire encounters the beam member, the beam member is deflected
at one end away from the longitudinal axis of the passageway and is resiliently urged
into electrical contact with the wire. Although push-in connectors are faster and
easier to use than "spring" type connectors, they are substantially more expensive
to construct and, therefore, their use has been limited.
Summary of the Invention
[0004] This invention provides a push-in electrical conductor that is inexpensive, easy
to manufacture and enables a plurality of wires to be quickly and easily interconnected.
[0005] An electrical connector is provided for electrically interconnecting a plurality
of wires, and includes an electrically insulating body having a plurality of parallel
passageways, each adapted to receive a portion of one wire. An electrically conductive
resilient contact is provided having first and second opposite major surfaces and
a peripheral edge surface around the major surfaces. The contact has in the plane
of the major surfaces a main portion and a plurality of arm portions projecting from
the main portion. Camming surfaces are provided in opposed pairs on the peripheral
edge surface of the contact for each wire, normally spaced at a distance less than
the diameter of the wires to be connected. At least one of each pair of opposed camming
surfaces is located on the peripheral edge of an arm portion. The contact is mounted
in the body with the major surfaces generally transverse to said passageways. Each
of the opposed pairs of camming surfaces is aligned with a different one of the passageways.
Each of the opposed pairs of camming surfaces is oriented so that engagement of the
end of one of the wires with the camming surfaces in a direction at a right angle
to the major surfaces will resiliently bend the adjacent arm portion away from the
opposite camming surface in a direction generally parallel to the major surfaces to
afford movement of the wire between the opposed pair of camming surfaces and provide
spring biased electrical and mechanical engagement between the contact and the wire.
Brief Description of the Drawing
[0006] The present invention will be further described with reference to the accompanying
drawing wherein like reference numerals refer to like parts in the several views,
and wherein:
Figure 1 is an isometric view of a push-in connector constructed according to this
invention.
Figure 2 is a top view of the push-in electrical connector of Figure 1.
Figure 3 is a cross sectional view taken generally along plane 3-3 of of Figure 2
illustrating engagement of a contact of the connector with three wires inserted into
the connector.
Figure 4 is a plan view of an alternate embodiment of the contact that could be used
in the connector of Figure 1.
Figure 5 is an end view of an alternative embodiment of the connector body of Figure
1 in which a contact is inserted through a common opening in an end of the connector
body.
Figure 6 is a partial cross-sectional view along plane 6-6 of the connector body of
Figure 5.
Description of the Preferred Embodiments
[0007] Referring now to Figures 1-3, the reference numeral 10 generally indicates an electrical
connector constructed according to the present invention. The connector includes a
body 11 constructed of electrically insulating material. Preferably, the connector
body 11 is molded from a thermoplastic material such as polyvinyl chloride, nylon
or polypropylene. The connector body 11 includes a first end 12 , a second end 14,
and a longitudinal axis 16 extending through the body between the first and the second
ends. A plurality of parallel sockets or passageways 18 extend into the body 11, generally
parallel to the longitudinal axis 16, each from an opening 19 at the first end 12.
Each of the passageways 18 is adapted for receipt of an exposed end portion 22 of
wire 20, guided by constructing frusto-conical openings 19 as shown. Although not
shown, it is within the scope of this invention to provide passageways 18 that extend
all the way through body 11, enabling insertion of a wire into either end 12 or 14
of the body.
[0008] Electrically conductive contact 24 includes opposing major surfaces and a peripheral
edge surface defining a main portion 25 of the contact and a plurality of resilient
arm portions 26 projecting from the main portion. The arm portions 26 lie between
the major surfaces in a common plane 28 generally transverse to the passageways 18
when the contact is mounted within the connector body. It is one of the primary advantages
of this invention that the contact 24 is economical to produce, such as by blanking.
[0009] Each of the arm portions extends into one of the passageways 18 when contact 24 is
mounted in the connector body. Although the contact 24 may be molded in place within
the body 11 of the connector, in the preferred embodiment of the invention a transverse
slot 30 is formed in the connector body to enable the contact to be inserted into
the connector body 11 and frictionally retained therein.
[0010] A plurality of pairs of camming surfaces 34 are formed on opposing parts of the peripheral
edge surface of the contact, each pair of camming surfaces for sliding engagement
with the end of a wire and each pair of opposing camming surfaces normally spaced
at a distance less than the diameter of the wires to be connected. At least one of
each pair of opposing camming surfaces is formed on the peripheral edge surface of
an arm portion 26. When the end portion 22 of wire 20 is inserted into a passageway
18, the end of the wire encounters one of the opposing pairs of camming surfaces 34
in a direction generally at right angles to the major surfaces of the contact. The
arm portion 26 is deflected away from the opposite camming surface in rotational direction
32. All of the movement of the arm portions 26 lies within the common transverse plane
28 between the major surfaces of the contact. The arm portion is resiliently urged
back in the opposite rotational direction 36 towards its relaxed position into secure
electrical contact with the exposed end portion 22 of the wire 20. Therefore, electrical
interconnection is established by contact 24 between all wires inserted into the connector.
Simultaneously, the wires are gripped by the contact so as to mechanically retain
the wire in engagement within the connector. If desired, the wires may each be independently
pulled from the passageway without damage to the wire or to the contact.
[0011] Figure 4 illustrates an alternative arrangement for the contact 24′, with the arms
26′ arranged in two spaced pairs and with a pair of intermediate flanges 38 projecting
from the main portion 25′ of the contact for more securely engaging the wire within
the connector.
[0012] Figures 5 and 6 illustrate yet another alternative embodiment 10′ of the connector
of this invention in which a common opening 39 is formed in the front end 12 of connector
body 11′. A contact (such as shown in Figure 3) is mounted in the body 11′ by insertion
in a longitudinal direction into common opening 39. The contact is mounted against
wall 40 Tapered tabs 42 are provided along with opposing concave surfaces 43 for each
passageway 18 to guide the end portion 22 of each wire 20 as it is inserted into the
passage.
[0013] In all other respects, these embodiments of the invention are as hereinabove described.
[0014] The present invention has now been described with reference to three embodiments
thereof. It will be apparent to those skilled in the art that many changes can be
made in the embodiments described without departing from the scope of the present
invention. Thus the scope of the present invention should not be limited to the structures
described in this application, but only by structures desribed by the language of
the claims and the equivalents of those structures.
1. An electrical connector (10) for electrically interconnecting a plurality of wires
(20), said connector (10) including an electrically insulating body (11) having a
plurality of parallel passageways, each of said passageways (18) adapted to receive
a portion of one wire (20), the invention characterized by:
an electrically conductive resilient contact (24) having first and second opposite
major surfaces and a peripheral edge surface around said major surfaces, said contact
having between said major surfaces a main portion (25) and a plurality of arm portions
(26) projecting from said main portion, said contact (14) further including a plurality
of pairs of opposing camming surfaces (34) formed on said peripheral edge surface
with each pair (34) normally spaced at a distance less than the diameter of the wires
(20) to be connected, to enable sliding engagement with one of the wires (20) and
at least one of each said pair of opposing camming surfaces (34) located on the peripheral
edge surface of an arm portion (26), said contact (24) being mounted in said body
(11) with said major surfaces generally transverse to said passageways (18) and each
of said pair of opposed camming surfaces (34) aligned with a different one of said
passageways (18) and oriented so that engagement of the end of one of the wires (20)
with the camming surfaces in a direction at a right angle to said major surfaces will
resiliently bend the adjacent arm portion away from the opposite camming surface in
a direction (32) generally parallel to said major surfaces to afford movement of the
wire (20) between said opposed camming surfaces (34) of said peripheral edge surface
and provide spring biased electrical and mechanical engagement between said contact
(24) and the wire (20).
2. The electrical connector of claim 1, further characterized in that a slot (30)
is formed in said connector body (11) generally transverse to said passageways (18)
for mounting said contact (24) within said connector body.